Lamp enclosure

ABSTRACT

The lamp enclosure comprises a rectangular open-ended casing having an inverted L-shaped flange circumscribing its inside surface adjacent to each end thereof, the lateral leg of each flange extending toward the adjacent end. A domed translucent lens is positioned within each end of the casing, and each lens has an outwardly turned rim around its perimeter that is placed in engagement with the lateral leg of the adjacent flange. A rectangular retaining ring is placed over each rim and fastened to the adjacent flange to hold each lens in place. A lamp holder assembly is pivotally secured to the inside surface of the casing and it includes a latch having a spring-loaded bolt for engaging an opening in a catch plate mounted in juxtaposition therewith, the catch plate having an inclined ramp to the front and back of the opening.

United States Patent 1 11 1 Dewhirst 1 1 LAMP ENCLOSURE [75] Inventor: Fred Arlington Dewhirst,

Indianapolis, Ind.

[73] Assignee: Bell Telephone Laboratories,

Incorporated, Murray Hill, NJ.

[22] Filed: Apr. 4, 1972 1 [21] Appl. No: 241,013

240/2 AT, 8.3, 51.11, 41 R, 41.3, 41.6, 44, 41.5,41.55;40/130,131,132;D96/12 R, 12

1451 Dec. 18, 1973 Primary 1Jxuminvr-Samuel S. Matthews Assistant Exuminer -Russcll E. Adams, Jr. Ar1orr1c v-W. L. Kcefauver [57] ABSTRACT The lamp enclosure comprises a rectangular openended casing having an inverted L-shaped flange circumscribing its inside surface adjacent to each end thereof, the lateral leg of each flange extending toward the adjacent end. A domed translucent lens is positioned within each end of the casing, and each lens has an outwardly turned rim around its perimeter that is placed in engagement with the lateral leg of the adjacent flange. A rectangular retaining ring is placed K over each rim and fastened to the adjacent flange to hold each lens in place. A lamp holder assembly is piv- 156] References cued otally secured to the inside surface of the casing and it U T STATES PATENTS includes a latch having a spring-loaded bolt for engag- 3,156,416 11/1964 Griffin 240 4155 ing an opening in a Catch plate mounted in juxtaposi- 2,831,964 4/1958 Dicdring 240/41 R tion therewith, the catch plate having an inclined 3,023,524 3/1962 Muse 1396/12 R ramp to the front and back of the opening.

FORElGN PATENTS OR APPLICATIONS 5 Cl 3 D F 385,495 12/1932 Great Britain 240 41 R alms rawmg gums q: t 1 1 a; t1 42 "at y 22 22 e 59, 62 1 ,1 s1 66 1; 26 124 i 65 .1 22 6 4 Qfi x 72 14 as: l 2 32 fi .m m

PAIENTEH on: 18 1915 3. 7801.284

' sum 10! 2 PATENTEnuEc 18 1915 I $780,2 4

sum 2 OF 2 LAMP ENCLOSURE FIELD OF THE INVENTION This invention relates to lamp enclosures and within that field to internally illuminated signs.

BACKGROUND ()I THE INVENTION 'lwo significant considerations in the design of an internally illuminated sign are simplicity of construction and ease of maintenance. The construction of the sign should be simple so that manufacture of the sign is facilitated and thereby made more economical. Once the sign is installed, it should be easy to service so that the user himself can maintain it or have it done at a modest cost.

SUMMARY OF THE INVENTION The sign of the present invention incorporates both simplicity of construction and ease of maintenance. In one embodiment it comprises a rectangular openended casing consisting of a ribbon-like web and an inverted L-shaped flange eircumscribing the inside sur' face of the web a short distance from each edge thereof. Each flange comprises an upstanding leg ex tending transversely from the web and a lateral leg extending transversely from the upstanding leg toward the adjacent edge of the web. A domed translucent lens is positioned within each end of the casing, and each lens has an outwardly turned rim around its perimeter that is placed in engagement with the lateral leg of the adjacent flange. A rectangular retaining ring overlies the top and outer edge of the rim of each lens and is fastened to the upstanding leg of the adjacent flange to secure the lens in place. The retaining ring in combina tion with the rim of the lens and the flange of the casing provide a water resistant seal.

A lamp holder assembly is pivotally mounted to the inside surface of the web and it includes a cold temper ature starting ring having a latch mounted thereon and supporting a circular fluorescent lamp on the front and back thereof. The latch includes a spring loaded bolt and a catch plate is mounted on the inside surface of the web in juxtaposition with the latch, the catch plate including an opening for accommodating the latch bolt and an inclined ramp to the front and back of the opening. The lamp holder assembly is disengaged from the catch plate by withdrawing the latch bolt from the opening and swinging the assembly toward either end of the casing. The assembly is relatched by merely pushing it back to the center position whereby the latch bolt moves back into the opening in the catch plate. This feature permits easy removal and replacement of one or both lamps from either end of the sign.

DESCRIPTION OF THE DRAWING FIG. l is a perspective view of an internally illumi nated sign in accordance with this invention;

FIG. 2 is an exploded perspective view of the sign with one retaining ring lens and circular lamp removed; and

FIG. 3 is an enlarged section taken along line 3-3 of FIG. l and showing the catch and latch plate for holding the lamp holder assembly in place.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawing, the internally illuminated sign includes a casing 10, a pair of translucent lenses 20, and a pair of retaining rings 30, all of which are rectangular in shape. The casing ltll is open-ended and as shown in FIGS. 2 and 3 it comprises a ribbon-like web 12 having an inverted L-shaped flange l4 circumscribing its inside surface a short distance from each edge. Each flange 14 comprises an upstanding leg 15 extending perpendicularly to the web 12 and a lateral leg 16 extending perpendicularly to the upstanding leg, the lateral leg extending toward the adjacent edge of the web. The casing I is advantageously an integral structure formed from a metal extrusion, the flanges 14 being notched to permit the bending of the extrusion to form the curved corners of the casing and the ends of the extrusion being welded together to unitize the easing.

Each lens 20 includes a face 22, a side wall 24 extending perpendicularly to the face, and an outwardly turned rim 26 extending perpendicularly to the side wall. The outside perimeter of the rim 26 of each lens .20 generally conforms to the inside perimeter of the web 12 of the casing 10. In addition, the outside perim eter of the rim 26 is smaller than the inside perimeter of the web 12 but larger than the inside perimeter of the associated flange 14. The inside perimeter of the rim 26 on the other hand is smaller than the inside perimeter of the associated flange 14-. Thus, each lens 20 sits inside of the web 12 and the face of the rim 26 engages the edge of the lateral leg 16 of the associated flange 14.

Each retaining ring 30 generally conforms to the shape of the casing and comprises a clamping portion 32 and a lip portion 34 extending laterally from the outside perimeter of the clamping portion. The inside perimeter of the clamping portion .32 is at least as great as the inside perimeter of the rim 26 of the associated lens 20, while the outside perimeter of the clamping portion is greater than the outside perimeter of the rim but smaller than the inside perimeter of the web 12. The lip portion 34 is greater in length than the thickness of the rim 26 but lesser in length than the combined thickness of the rim and the length of the lateral leg 16 of the associated flange 14. As a result, when the retaining ring 30 is placed in engagement with the associated lens 20, the clamping portion 32 abuts against the rim 26 and the lip portion 34 encompasses the edge of the rim.

As seen most clearly in FIG. 3, each retaining ring 30 is secured to the associated flange 14 by fasteners 35 that have threaded end portions and unthreaded shank portions between the heads and the threaded portions that are of smaller diameter than the major diameter of the threaded portions. The fasteners 35 are screwed through the clamping portion 32 of the ring into the upstanding leg of the flange, the rim 26 of each lens having openings through which the fasteners extend. The fasteners 35 draw the retaining ring toward the flange l4 and cause the clamping portion 32 to press the rim 26 against the lateral leg 16 of the flange. The tight engagement of the flange 14, rim 26, and retaining ring 30 in combination with the overlapping of the ring with the flange provide a water resistant seal for the sign. Furthermore, the clamping portion 32 is spaced from the upstanding leg 15 a greater distance than the length of the threaded portions of the fasteners 35, and therefore when the fastenersare unthreaded from the upstanding leg to permit removal of the retaining ring 30 and lens 20 from the casing 10, the fasteners are still captive in the retaining ring. There is therefore no problem of losing the fasteners 35.

As shown in FIG. 2, a lamp holder assembly 40 is mounted between the ends of the casing 10. The lamp holder assembly 40 comprises a cold temperature starting ring 42 supported on a pair of spaced arms 44, the arms being pivotally mounted on a pair of brackets 45 (only one of which is shown) affixed to the inside surface of the web l2. The arms 44 space the starting ring 42 from the sides of the casing and permit the start ing ring to be pivoted toward either end of the casing. Three lamp clips 48 spaced approximately l80 apart are joined to the starting ring 42 and support a circular fluorescent lamp 50 on each side of the ring, the clips holding the lamps a short distance from the sides of the ring.

Finally, the lamp holder assembly 40 includes a latch 60 attached to the starting ring 42 in juxtaposition with a catch 70 mounted on the inside surface of the web 12. As shown most clearly FIG. 3, the latch 60 comprises a cylindrical bolt 62 having a tapered lower end. The bolt 62 is supported by the legs of a U-shaped bracket 64 so as to be slidably displaceable along its axis, and a spring 65 biases it toward the catch 70. Upward movement of the bolt 62 is limited by the compression of the spring 65, while downward movement is limited by the catch 70 when the lamp holder assembly 40 is in its latched position and by a retaining ring 66 when the assembly is in its unlatched position. A second retaining ring 68 is provided at the upper end of the bolt 62 to provide a gripping surface for disengaging the bolt from the catch 70.

The catch 70 comprises a catch plate 72 mounted on a support 74. The catch plate 72 and support 74 have an opening in the center thereof that is somewhat smaller in diameter than the lower portion of the bolt 62, and the catch plate has an inclined ramp to the front and back of the opening. Thus, after the bolt 62 has been disengaged from the opening in the catch 70 and the lamp holder assembly 40 has been swung toward either end of the casing 10 to replace one or both of the lamps 50, the latch 60 is reengaged by merely swinging the lamp holder assembly back to the center of the casing. The tapered lower end of the bolt 62 engages one of the inclined ramps of the catch plate 72 and the bolt is deflected upward until it moves into registration with the opening in the catch plate, whereupon the spring 65 snaps it into place. The tight fit between the tapered lower end of the bolt 62 and the opening in the catch 70 eliminates any rattling of the lamp holder assembly 40.

Referring again to FIG. 2, electrical power for the fluorescent lamps 50 is provided from ballasts 80 by way of sockets 82. The ballasts 80 are connected to a waterproofjunction box 84 which is in turn connected to an external power supply through a waterproof strain relief 86.

Although a specific embodiment of the invention has been shown and described, it will be understood that it is but illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as defined in the appended claims.

What is claimed is:

l. A lamp enclosure comprising:

an open-ended casing including a web having a flange circumscribing its inside surface a short distance from the open end of the casing;

a lens positioned on the open end of the casing, the outside perimeter of the lens generally conforming to but being smaller than the inside perimeter of the web of the casing whereby permimeter of the lens is accommodated within the web, the outside perimeter of the lens further being larger than the inside perimeter of the flange of the casing whereby the perimeter of the lens is positioned in juxtaposition with the flange, the thickness of the perimeter of the lens and the location of the flange being such that the perimeter of the lens is recessed within the open end of the casing;

a retaining ring positioned in engagement with the perimeter of the lens and fastened to the flange of the casing, the outside perimeter of ther retaining ring generally conforming to but being smaller than the inside perimeter of the web and the inside perimeter of the retaining ring being smaller than the outside perimeter of the lens; and

a lamp holder assembly pivotally mounted to the inside surface of the web, the assembly including a latch, and a catch mounted to the inside surface of the web in juxtaposition with the latch.

2. A lamp enclosure as in claim 1 wherein the flange has an upstanding leg extending transversely from the web and a lateral leg extending transversely from the upstanding leg toward the open end of the casing, and the outside perimeter of the retaining ring is larger than the outside perimeter of the lens and includes a lip that encompasses the perimeter of the lens and overlaps the lateral leg of the flange.

3. A lamp enclosure as in claim 1 wherein the flange has an upstanding leg extending transversely from the web and a lateral leg extending transversely from the upstanding leg toward the open end of the casing, the portion of the lens adjacent to its perimeter engages the lateral leg of the flange, and the outside perimeter of the retaining ring is larger than the outside perimeter of the lens and includes a lip that encompasses the perimeter of the lens and overlaps the lateral leg of the flange, the thickness of the perimeter of the lens, location of the flange, and thickness of the retaining ring being such that the perimeter of the lens and the retaining ring are recessed within the open end of the casing.

4. A lamp enclosure as in claim 1 wherein the latch includes a spring loaded bolt, and the catch includes a plate having an opening therein for accommodating the bolt and an inclined ramp on either side of the opening.

5. A lamp enclosure as in claim 4 wherein the bolt has a tapered end and the opening in the plate accommodates a portion of the tapered end of the bolt. 

1. A lamp enclosure comprising: an open-ended casing including a web having a flange circumscribing its inside surface a short distance from the open end of the casing; a lens positioned on the open end of the casing, the outside perimeter of the lens generally conforming to but being smaller than the inside perimeter of the web of the casing whereby permimeter of the lens is accommodated within the web, the outside perimeter of the lens further being larger than the inside perimeter of the flange of the casing whereby the perimeter of the lens is positioned in juxtaposition with the flange, the thickness of the perimeter of the lens and the location of the flange beiNg such that the perimeter of the lens is recessed within the open end of the casing; a retaining ring positioned in engagement with the perimeter of the lens and fastened to the flange of the casing, the outside perimeter of ther retaining ring generally conforming to but being smaller than the inside perimeter of the web and the inside perimeter of the retaining ring being smaller than the outside perimeter of the lens; and a lamp holder assembly pivotally mounted to the inside surface of the web, the assembly including a latch, and a catch mounted to the inside surface of the web in juxtaposition with the latch.
 2. A lamp enclosure as in claim 1 wherein the flange has an upstanding leg extending transversely from the web and a lateral leg extending transversely from the upstanding leg toward the open end of the casing, and the outside perimeter of the retaining ring is larger than the outside perimeter of the lens and includes a lip that encompasses the perimeter of the lens and overlaps the lateral leg of the flange.
 3. A lamp enclosure as in claim 1 wherein the flange has an upstanding leg extending transversely from the web and a lateral leg extending transversely from the upstanding leg toward the open end of the casing, the portion of the lens adjacent to its perimeter engages the lateral leg of the flange, and the outside perimeter of the retaining ring is larger than the outside perimeter of the lens and includes a lip that encompasses the perimeter of the lens and overlaps the lateral leg of the flange, the thickness of the perimeter of the lens, location of the flange, and thickness of the retaining ring being such that the perimeter of the lens and the retaining ring are recessed within the open end of the casing.
 4. A lamp enclosure as in claim 1 wherein the latch includes a spring loaded bolt, and the catch includes a plate having an opening therein for accommodating the bolt and an inclined ramp on either side of the opening.
 5. A lamp enclosure as in claim 4 wherein the bolt has a tapered end and the opening in the plate accommodates a portion of the tapered end of the bolt. 